Description
Zoisite first known as saualpite, after its type locality, is a calcium aluminum hydroxy sorosilicatebelonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH).
Zoisite occurs as prismatic, orthorhombic (2/m 2/m 2/m) crystalsor in massive form, being found in metamorphic and pegmatitic rock. Zoisite may be blue to violet, green, brown, pink, yellow, gray, or colorless. Blue crystals are known under the name tanzanite.
